1. Field of the Invention
The present invention relates to a heater with temperature detecting device, which includes a thin laminated sheet heater and a temperature detecting device; a battery structure including the heater with temperature detecting device; and a heater unit.
2. Description of Related Art
In some of heaters provided with a temperature detecting device (a temperature sensor or the like) to detect the temperature of the heater, the temperature detecting device is fixed to the surface of the heater.
JP2004-356087A discloses a heater including a base, a heating element (a heater element) placed on the base, and a fixing material provided on the base so as to cover the heating element. A first embodiment of JP '087A teaches a heater with a temperature detecting device (a temperature sensor) embedded together with the heating element in the fixing material.
Recently, there are increasing demands for reduction in thickness of heaters. Accordingly, a laminated film heater including a heater element formed of metal foil in a predetermined pattern and two insulating resin films (polyimide film or the like) between which the heater element (see JP2004-355882A) is interposed.
This laminated film heater is used to for example heat a battery under a low temperature condition to improve output characteristics of the battery. To be concrete, there has been proposed a technique in which a laminated film heater is attached to the bottom of a battery for vehicle to heat by use of a household power source (see JP60(1985)-192367U).
Meanwhile, the aforementioned laminated film heater which has the surface made of the insulating resin film would be apt to cause large unevenness of surface temperature. This results in a problem that a body to be heated (a battery for vehicle and others) could not be heated uniformly. To solve this problem, recently, a laminated sheet heater has been proposed in which a metal sheet is laminated on an outer surface of an insulating resin film. Since the metal sheet is more superior in heat conductivity than the insulating resin film, such laminated sheet heater can reduce the heating unevenness.
On the other hand, the above laminated sheet heater has been required to include a temperature detecting device for detecting the temperature of the heater. However, if the temperature detecting device (a temperature sensor or the like) is fixed to the surface of the laminated heater, the temperature detecting device will be cooled by outside air, leading to incorrect detection of the heater temperature.
Further, the laminated sheet heater is very thin and hence it does not allow the temperature detecting device to be embedded in the fixing material or the like together with the heater element (heating element) as shown in the first embodiment of JP '087A.